1. Field of the Invention
This invention relates to a method and apparatus for temporarily covering openings, such as spouts and mouths, of bottles, cans and other containers.
2. Description of the Prior Art
In a series of processes handling many containers, sometimes there arises a need to temporarily close an opening or openings of each container. In the manufacturing of drum containers, for example, a temporary cap is fitted over the spout of each drum when the exterior of the drum is to be painted so that no paint gets inside. Other examples can be found in the food and medicine industries, too. When washed bottles are sent to the next process or temporarily put aside, the mouth of each bottle is temporarily covered so that no dust, waterdrops or other foreign matters gets inside. Such temporary covers are detached on completion of painting or before the contents are filled.
Caps, cap-like covers and elastic stoppers having an elastic portion adapted to fit in or over the opening are extensively used as temporary covers.
Because of the design necessary to fit the elastic portion in or over the opening, such conventional temporary covers must be exactly positioned over the opening to be covered. Attaching and detaching such temporary covers requires a considerable amount of labor. The need to pay close attention and the large amount of labor required has made it difficult to continue manual attaching and detaching work for long periods of time. Automatic attaching and detaching necessitate a high-precision positioner and a high-power actuator. The prior art automated systems have been complex, bulky and expensive.